Method of starting internal combustion engines



July 12; 1938. A. CALLSEN 2,123,711

METHOD OF STARTING INTERNAL COMBUSTION'ENGINES Filed April 2, 1936 IIHI I I Patented July12,1938 I i 2,123,111

METHOD OF STARTING INTERNAL COMBUS-' TION ENGINES Albert Callsen, Stuttgart, Germany, assixnor to Robert Bosch Gesellschai't mit beschrankter Haftung, Stuttgart, Germany Application April 2, 1936, Serial No. 72,874 1 Germany April 25, 1935 '1 Claims. (Cl. 123-179) The present invention relates to the starting ther, the cylinder walls are also preliminarily of internal combustionengines. warmed up by the ignitions which occur, even if Large internal combustion engines are started they are only weak. The starting shock that from cold principally in two ways. In one methnow follows can now produce a very rapid piston ed a starting apparatus is employed in which movement which continues over several revo- 5 energy is stored up in some way, for example lutions, whereby a sufflcient vaporization of the by means of inertia masses, or in which great injected fuel is obtained and only little heat is pressures are suddenly produced by explosive conducted away, so that powerful ignitions at substances. It is a feature common to these once result which assist the starter and rotate starters that they start the engine with a jerk, the engine quickly several times so that it starts 10 and in doing so vaporize a fuel mixture injected with certainty. into the cylinders to such a degree that it can Three examples of construction of the invenbe ignited. These starting apparatus do their tion are diagrammatically shown in the accomwork satisfactorily when the engine is warm, panying drawing, in which:-- but not when it is very cold and has been stopped Figure 1 shows a starting apparatus having 15 for a long time. In this case, the starting appaan electric motor and a powder gas starter. ratus, which functions quite easily in. starting Figure 2 is a side elevation, partly in section, a warm engine, is usually unable to cause the of the apparatus.

engine to make more than about three quarters Figure 3 shows a further modified form of of a revolution because a large part of the startconstruction. 3 ing energy is consumed by the increased fric- In Figure 1 astarting apparatus is shown,

tional resistance caused by the viscous lubricatconsisting of two main parts, an electric starting oil. The result of this is that not all the ing motor i and a compressed gas starting cylinder pistons come into the ignition position, means 2, which jointly work on a clutch member and furthermore, the mixture is so badly va- 3, here formed as aclutch dog 4, which is adapted porized that it can only be fired with difllculty. to engage in a dog 5 on the crank-shaft 6 of an In this case, the starting efficiency of the starter internal combustion engine.

is not assisted or only very slightly assisted by On the armature shaft 1 of the electric motor the ignitions in the cylinders. The engine must is mounted a small toothed pinion 8, which is therefore often be several times started before in engagement with the planet-wheels 9 of a 30 it begins to run. Under exceptionally cold cirplanet-gear, which in theirturn co-operate with cumstances starting is often not possible at all. an internally toothed wheel I 0 secured on the In the other method, the engine is turned motor casing. The planet-wheels are mounted over slowly several times and a mixture injected on pins ll, fixed in a plate l2. A shaft I3 is into the cylinder and ignited by means of an firmly connected to this plate, and on this shaft 35 auxiliary starter. The main drawback of this a sleeve I 4 is arranged so as to be longitudinally mode of starting consists in that when the displaceable but prevented from relative rotaengine is cold, the mixture is .so little vaporized, tion. The sleeve is connected to the dog 4 and so much heat is withdrawn from it, that through a free-wheel clutch IS. A lever 22 it cannot be ignited, or only ignited with difliserves for moving the sleeve.

culty. The engine must therefore be rotated for A toothed wheel I6 is provided externally on a long time until such powerful ignitions take the dog 4 and is connected to the dog 4 also by place that it continues to run of itself. In this a free-wheel clutch II. On this toothed wheel case the danger exists of the plugs becoming a toothed rackhar l8 acts on operating the sooted up by the injection of too much fuel. compressed gas starting means 2, which includes The drawbacks mentioned are avoided acapiston is which carries the rackbar I8 and cording to the invention by the engine being first moves in a cylinder 20. On the cylinder a derotated slowly several times and following this, vice 2| is provided in which a cartridge can be started with a jerk. This new method of startfired that supplies the necessary gas pressure.

ing engines has the advantage that by the slow The apparatus works in the following way; 50 Starting he St 0f the engine with a jerk To start the internal combustion engine, the is prepared for. By the slow starting the fricdriver first switches on the electric motor, and tiondue to rest is overcome and the frictional then by the lever 22 brings the dog 4 into enresistance reduced, because the viscous lubrigagement with the dog 5 on the crank-shaft.

cating oil is thinned by the injected fuel. Fur- The starting motor and the transmission of the 66 planet-gear is so proportioned that it rotates.

the engine slowly several times. During the slow starting an easily ignitable mixture is injected into the cylinders. .After a few revolutions of the internal combustion engine, the driver now puts the compressed gas starter into operation. The toothed rackbar I8 engages in the toothed wheel IS on the dog 4 and sets the crank-shaft with a jerkinto a very strong rotation. This sudden and very rapid movement of the crank-shaft causes an energetic eddying and vaporizing of the mixture in the cylinders of the internal combustion engine, and the mixture owing to the sudden compression is greatly heated, and of this heat only little is lost by conduction, because the starting operation is very quickly completed.

When the engine is running under its \own power, the dog 4 is pushed back. The two freewheel devices enable each of the starting apparatus to work independently of the other. The essence of the mode of working described consists in that the internal combustion engine is first slowly revolved several times and then with a jerk rapidly further revolved.

In the second form of construction, the internal combustion engine is also slowly rotated by an electric starting motor, as in the first example. The sudden or jerky rapid further rotation is effected by starting cartridges 40, which are directly built on to the cylinders of the internal combustion engine. The cartridges are fired by a conventional timing device 4|, which is so arranged and driven that it causes the firing of. the cartridges automatically, each in proper phase relation to the associated cylinder piston. This device comprises a stationary contact disc a having a series of contacts b each connected with one of the cylinder cartridges. A brush 0 is carried by a gear d, the gear 11 being drivenat half ,the speed of the crank shaft by means of a geare fast on the crank shaft. The brush 6 is conductively connected to a contact ring 1 carri'ed bythe gear (1. A stationary brush g is in constant engagement with the conductive ring 1.

The firing of the cartridges is controlled by a switch 42 which may be closed by the operator to connect the brush 9 with a source of current. The contacts b are so located that after the switch 42 has been closed, each cartridge will be fired at the beginning of the power stroke of the piston cylinder with which the cartridge is associated.

I declare that what I claim is:

1. A method of starting internal combustion engines wherein fuel is delivered to the cylinders of the engine during starting, consisting in first turning over the engine by means of a power motor through at least one cycle at low speed through a reduction gearing, and subsequently suddenly imparting a high kinetic energy impulse from a. separate energy source to turn the engine at high speed in order to energetically whirl and vaporize the fuel mixture, the ignition of which subsequently drives the engine.

2. A method of starting internal combustion engines wherein fuel is sprayed into the cylinders of the engine during starting, consisting in electrically turning over the engine through at least one cycle by kinetic energy from an electric motor through a reduction gearing and subsequently imparting a high kinetic energy impulse from a separateenergy source to energetically vaporize the fuel mixture, the ignition of which subsequently drives the engine.

3. A method of starting internal combustion engines wherein fuel is sprayed into the cylinders of the engine during starting, consisting in electrically turning over the engine through at least one cycle thereof at a relatively low speed and thence energizing an explosive cartridge, one for each cylinder of the engine to be started, to impart a relatively high kinetic energy impulse directly on the pistons of the engine to be started.

4. Apparatus for starting internal combustion engines comprising a starting motor, a member adapted to be clutched to a moving part of the engine to be started, a transmission gearing between said starting motor and said clutch member for driving the latter at a relatively low speed, a second source of. energy, a transmission drive between said second source of energy and said clutch member for driving the latter at a relatively high speed and means to energize said second source of energy after said first transmission drive has turned over said engine through at least one complete cycle. v

5. Apparatus for starting internal combustion engines comprising a starting motor, a member adapted to be clutched to a moving part of the engine to be started, a transmission gearing between said starting motor and said clutch member for driving the latter at a relatively low speed, a compressed gas charge operated energy source,

a transmission drive between said compressed gas charge operated energy source and said clutch member for driving the latter at a relatively high speed and means to energize said compressed gas charge operated energy source after said first transmission drive has turned over said engine through at least one complete cycle.

6. Apparatus for starting internal combustion engines comprising a starting motor, a member adapted to be clutched to a moving part of the,

engine to be started, a transmission drive between said starting motor and said member for driving the latter at arelatively low speed, a freewheel clutch in said transmission drive, a compressed gas charge operated energy source, a. transmission drive between said energy source and said clutch member, a free-wheel clutch in said transmission drive and means to energize said compressed gas charge energy source after said engine has been turned over through at least one complete cycle of said starting motor.

7. Apparatus for starting internal combustion engines comprising an electrically operated starting motor, a member adapted to be clutched to a moving part of the engine to be started, a transmission drive between said starting motor on said member for driving the latter at a relatively low speed, a cylinder, a piston displaced within said cylinder by the action of a compressed gas charge, a rack bar carriedby said piston, a toothed wheel rotated by said rack bar, a free-wheel clutch between said toothed wheel and said clutch member, means to energize said gas charge for displacing said piston after said motor has rotated said clutch member to turn over said engine through at least one complete cycle, whereby a high kinetic energy is imparted to said clutch member.

ALBERT CALLSEN. 

